Marine birds

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Black-browed albatross (Thalassarche melanophris) taking off. The species has experienced an improvement in its threat status (Near Threatened to Least Concern), due to the wider implementation of fisheries bycatch mitigation measures. (© Alistair McInnes)

31%
of 74 assessed species are
Threatened

9%
of 74 assessed species are
Endemic

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Key findings

• All seven seabird species endemic to the Benguela upwelling ecosystem are classified as regionally threatened for the first time.
• Africa’s only penguin species, the African Penguin, is now the world’s most threatened penguin species, having been uplisted from globally Endangered to globally Critically Endangered.
• Albatrosses constitute the largest group of threatened seabird species largely due to incidental mortalities associated with interactions with commercial fishing vessels and due to predation by invasive mammals like house mice at their breeding colonies.
• Efforts are underway to restore Marion Island’s ecosystem and the many seabird species that breed there with the Mouse-Free Marion Project, a partnership between DFFE and BirdLife South Africa.

Threat status and pressures

Albatrosses constitute the most threatened group of seabirds in South African waters with nine threatened species including five Endangered and one Critically Endangered species, the Tristan albatross¹. The latter species has approximately 8000 individuals remaining, the majority of which breed on Gough Island (Banda 2025c). All threatened albatross species that regularly occur in South African waters are exposed to threats at sea in the form of bycatch from longline and trawl fisheries (Maree et al. 2014, Rollinson et al. 2017;¹) (Figure 1). Albatrosses, petrels and shearwaters are also threatened at their breeding colonies by invasive alien mammals such as house mice which prey on these species that breed on Marion and Gough islands. All three threatened penguin species, African, Gentoo and Southern rockhopper penguins are exposed to a plethora of threats including climate change, disease, pollution and human disturbance (Hagen 2025, Makhado et al. 2025b, Makhado and Crawford 2025a) (Figure 2). Cormorants have a high proportion of threatened species which include two Endangered species (Cape and Bank cormorants) that are endemic to the cool Benguela upwelling ecosystem off South Africa and Namibia (Box 1). Just over a quarter of the global population of the regionally Endangered Crozet Shag breed at the Prince Edward Islands where their declining population is likely linked to prey availability and exposure to human disturbance (Makhado and Crawford 2025b). Two Endangered tern species, Kergeulen tern on Prince Edward Islands and Damara tern from mainland southern Africa both have very small populations of approximately 50 pairs within the region; the primary reason for their Endangered status (Makhado et al. 2025c, Whittington 2025).

Figure

Figure 1. Summary threat status of South African seabirds species; categories follow the IUCN 3.1 Red List Categories and Criteria with an additional national category of Rare added for range-restricted, localised endemics that are not declining. The portion of species in each category is shown in the larger circle (A), and the proportion of endemic species per category is shown in the smaller circle (B). The total number of taxa that have been assessed is shown in the inner circle.

Data

Table 1. Summary of threat status of South African seabird species for all species and endemic species. Number of species indicated for each IUCN Red List category.

Taxon	Extinct	Extinct in the Wild	Regionally Extinct	Critically Endangered (Possibly Extinct)	Critically Endangered	Endangered	Vulnerable	Near Threatened	Data Deficient	Rare	Least Concern	Total
Indigenous seabirds	0	0	0	0	2	14	13	14	0	0	31	74
Endemic seabirds	0	0	0	0	1	2	1	2	0	0	1	7

Figure 2. Number of seabird species for each family group and for each threat category. Biological resource use includes fisheries bycatch and resource competition by fisheries for common prey species.

Trends - The Red List Index

The trend in species status over time was measured using a global standard indicator, the IUCN Red List Index (RLI) of species². The RLI is calculated for specific taxonomic groups based on genuine changes in Red List status over time. The RLI value ranges from 0 to 1. At a value of 1, all species are at low risk of extinction (Least Concern), while a value of 0 indicates that all species are extinct.

Figure 3. The Red List Index (RLI) for bird taxa assessed in South Africa. The slope of the line indicates the rate at which species within each taxonomic group are becoming more threatened over time. The lower the value, the faster the group of species is heading towards extinction (if the value is 0, all species are extinct).

Seabirds constitute the most threatened group of birds in South Africa¹ and globally (Dias et al. 2019). Despite this negative comparative status among bird groups, the number of uplisted seabird species in South Africa has been balanced by the same number of species that have been downlisted, i.e. four species for each, in the 2025 regional Red List assessment. Examples of species that have acquired improved conservation status include the Black-browed albatross (downlisted from Near Threatened in 2015 to Least Concern in 2025, (Angel 2025) and Spectacled petrel (downlisted from Vulnerable in 2015 to Near Threatened in 2025, (Banda and Smit-Robinson 2023). The former species was previously exposed to high levels of unmitigated fisheries bycatch in both their breeding and non-breeding ranges – a situation that has improved through the scaling up of bycatch mitigation measures throughout the range of this species. Spectacled petrel populations have increased since the local extinction of feral pigs on their major breeding colony on Inaccessible Island in the 1980s. Uplisted species include two pelagic species that breed in the Prince Edward Islands, Light-mantled albatross and Grey petrel both of which experience significant mortalities due to longline fishery bycatch; both these species are also susceptible to mortalities by invasive mice on Marion Island (Banda 2025a & b).

Spectacled petrel (Procellaria conspicillata) populations have increased since the local extinction of feral pigs on their major breeding colony on Inaccessible Island in the 1980s. (© Peter Ryan)

NoteBox 1: Benguela endemic seabirds - a special group of seabirds on the brink.

Benguela endemic seabirds - a special group of seabirds on the brink

Cape cormorant – Endangered. (© Alistair McInnes)

African penguin – Endangered. (© Alistair McInnes)

Hartlaub’s gull – Vulnerable. (© Alistair McInnes)

Bank cormorant – Endangered. (© Alistair McInnes)

Cape gannet – Endangered. (© Alistair McInnes)

Damara tern – Endangered. (© Peter Ryan)

Crowned cormorant – Vulnerable. (© Alistair McInnes)

The Benguela upwelling ecosystem supports seven endemic seabird species. The regional Red List assessment of birds in 2025 marked the first instance in which all seven of these species were classified as threatened. Three species: African penguin (now globally Critically Endangered), Cape cormorant ( globally and regionally Endangered) and Cape gannet (regionally Vulnerable and globally Endangered) have been classified as regionally threatened for greater than a decade largely due to their reliance on small pelagic fish, such as sardine and anchovy, and threats associated with the availability of this prey such as resource competition by the commercial purse-seine fishery and climate driven range shifts in these prey species (Hagen 2025, McInnes et al. 2025a, Pistorius 2025). Hartlaub’s gull and Crowned cormorant have been uplisted to Vulnerable due to a combination of threats including human disturbance at breeding colonies, predation and diseases such as highly pathogenic avian influenza (Makhado et al. 2025a, McInnes et al. 2025b). Bank cormorants have been listed as regionally threatened throughout this century due to a combination of threats including a decline in their major prey species, most notably west coast rock lobster, but also breeding failure associated with climate change driven intensification of storm events and heat exposure (Shaw and Crawford 2025). The relatively small population of Damara terns in South Africa have continued to decline largely due to disturbance at their coastal nesting sites (Whittington 2025).

Recovery effort

As part of the Global Biodiversity Framework (GBF) Target 4, signatories are committed to taking urgent action to halt human-induced extinctions, reduce species’ risk of extinction, and improve their conservation status by 2030. Achieving this target requires coordinated efforts to prevent and reverse species declines, recover and conserve populations, and maintain genetic diversity, particularly among threatened species. South Africa has initiated a process for each of the taxonomic groups that have been comprehensively assessed following the IUCN Red List criteria, to identify and prioritise species that are in urgent need of interventions to promote their recovery to contribute to achieving the GBF Target 4 goals.

NoteBox 2: Mouse-Free Marion.

Globally, invasive species are among the greatest threats to seabirds. South Africa’s sub-Antarctic Prince Edward Island group (comprising Marion and Prince Edward islands) provides critical breeding grounds for Southern Ocean seabirds. In total, 29 seabird species breed on Prince Edward Island while 28 species breed on the larger Marion Island. Together, these islands host nearly half of the global population of Wandering albatrosses (Diomedea exulans). However, Marion Island’s seabirds face a severe threat: invasive House mice (Mus musculus), accidentally introduced in the 1800s, are pushing the island’s ecosystem, and its seabird populations, towards ecological collapse.

In partnership with the South African Department of Forestry, Fisheries and the Environment, BirdLife South Africa established Saving Marion Island’s Seabirds: The Mouse-Free Marion (MFM) Project in 2021. This project’s objective is the eradication of House mice to restore Marion Island’s biodiversity and ecological integrity. The MFM Project is currently in its planning and preparatory phase, with the expected date of the eradication operation dependent on securing required funding and regulatory approvals well before the operation.

19 of the 28 seabird species breeding on Marion Island are at risk of local extinction due to the impacts of invasive House mice. Marion Island’s warming and drying climate is creating improved conditions for mice. Having already driven many invertebrate populations to negligible levels, some of which are now at risk of extinction, mice have turned to eating seabird eggs, chicks, and more recently even adult birds. Given projections of ongoing climate change, this threat is likely to intensify.

The eradiation of mice to restore Marion Island requires broadcasting of specially-formulated rodenticide bait from spreader buckets slung beneath helicopters guided by GPS technology. Every aspect of the operation—from timing and bait selection to helicopter use, loading techniques, GIS mapping tools, and health and safety procedures—is based on previous operational experience and best practice principles developed from decades of island restoration work worldwide and refined by island-specific trials, and extensive ecological research on Marion Island.

Around the world, numerous islands have been restored through the eradication of invasive species, particularly introduced predators. The dramatic recoveries of native flora and fauna in these places provide strong evidence that similar interventions can deliver lasting biodiversity gains. For seabirds, removing a major threat not only allows populations to rebound but also strengthens their resilience against other pressures, such as climate-change driven ocean changes and fisheries bycatch. Moreover, this intervention will also help buffer seabird populations against emerging threats, including diseases such as the Highly Pathogenic Avian Influenza. See the PEI NBA report for further details.

Grey-headed albatross chicks on Marion Island. (© Ben Dilley)

Conducting bait trials on Marion Island. (© Michelle Risi)

Wounded wandering albatross after being preyed on by House mice on Marion Island. (© Michelle Risi)

NoteBox 3: Albatross Task Force seabird conservation efforts.

Of the 18 species of albatrosses that breed in the Southern Ocean, 12 species forage in South African waters, all of which are impacted by fishing activities in the form of bycatch. Five of the 12 species of albatross breed on the Prince Edward Islands, including 40% of the world’s Wandering albatross population. An additional 19 species of seabirds are impacted by bycatch, including 14 that breed in South Africa, of which five are Benguela Current endemics. Of the total 31 species impacted by bycatch, 14 (35%) are threatened with extinction, with an additional 7 species classified as Near threatened by the IUCN.

At the forefront of dealing with seabird bycatch issues is BirdLife South Africa’s Albatross Task Force (ATF) team, active since 2004 and part of an international team of experts working directly with fishing crews and governments to implement and legislate seabird bycatch mitigation measures. The ATF has been instrumental in the development and adoption of Bird-scaring Lines (BSLs), a key mitigation measure that significantly reduces seabird interactions with trawl cables and baited hooks. In 2010, research carried out by the ATF demonstrated that the use of BSLs reduced annual seabird bycatch in the demersal hake trawl fishery by 90%, from an estimated 9,300 birds being killed annually (2004-2005) to under 1000 seabirds in 2010 (Maree et al. 2014).

An 85% reduction in seabird bycatch by foreign longline vessels operating in South African waters was achieved through the incorporation of strict management legislation in 2008, reducing the estimated 2,800 birds killed annually between 1998-2005 to an average of 340 birds killed per year between 2006-2013 (Rollinson et al. 2017).

Ensuring compliance with mitigation is key to sustaining seabird bycatch reductions and in addition to training fisheries observers and monitors, the ATF is actively promoting and partnering in researching electronic monitoring tools such as the Imvelo BSL Tension Device. A simple device that measures the tension exerted by the BSL as it is dragged through the water, providing real-time data and informing compliance with this measure.

The National Plan of Action for Seabirds (NPOA-S) for the period 2025-2030 has recently been drafted by the Department of Forestry, Fisheries and the Environment in collaboration with the ATF. The document once adopted will provide a national framework and strategic actions aimed at further reducing seabird bycatch across South Africa’s fisheries and promote sustainable fishing practices that align with international conservation standards.

One of the major threats to the Critically Endangered African penguin is a lack of food, driven by competition with the fishing industry and climate-induced changes in fish distribution and abundance. While there are several initiatives in place to address this, a novel conservation measure is to establish new penguin breeding colonies in areas of higher fish abundance where there is little competition from the fishery. This work is being led by BirdLife South Africa in partnership with CapeNature and SANCCOB. In late 2018, work began on the eastern edge of the De Hoop Nature Reserve. A small colony was established there in the early 2000s but was abandoned by about 2008 due to predation by caracal. A predator-proof fence was installed to protect the headland, which is monitored using CCTV cameras along the fence and trail cameras to determine the general abundance and movements of predators.

The first phase of the project was to attract penguins to the site naturally, using social attraction techniques that mimic an already existing colony. Life-like penguin decoys were placed at high vantage points and a speaker playing penguin calls was set up. These were in place for 2 years before the second phase was implemented. This was to release hand-reared penguin fledglings. Abandoned eggs and chicks rescued from other colonies, are hand-reared by SANCCOB before being released back into the wild at the age they would fledge naturally. Since 2021, over 300 fledglings have been released.

Bird-scaring lines preventing seabird mortalities from cable interactions in use by a demersal trawl vessel. (© Otto Whitehead)

NoteBox 4: De Hoop for penguins: Creating a new breeding colony for African Penguins.

One of the major threats to the globally Critically Endangered African Penguin (regionally Endangered) is a lack of food, driven by competition with the fishing industry and climate-induced changes in fish distribution and abundance. While there are several initiatives in place to address this, a novel conservation measure is to establish new penguin breeding colonies in areas of higher fish abundance where there is little competition from the fishery. This work is being led by BirdLife South Africa in partnership with CapeNature and SANCCOB. In late 2018, work began on the eastern edge of the De Hoop Nature Reserve. A small colony was established there in the early 2000s but was abandoned by about 2008 due to predation by caracal. A predator-proof fence was installed to protect the headland, which is monitored using CCTV cameras along the fence and trail cameras to determine the general abundance and movements of predators.

The first phase of the project was to attract penguins to the site naturally, using social attraction techniques that mimic an already existing colony. Life-like penguin decoys were placed at high vantage points and a speaker playing penguin calls was set up. These were in place for 2 years before the second phase was implemented. This was to release hand-reared penguin fledglings. Abandoned eggs and chicks rescued from other colonies, are hand-reared by SANCCOB before being released back into the wild at the age they would fledge naturally. Since 2021, over 300 fledglings have been released.

Three wild adult African penguins arrived at the colony in June 2022. It is unknown where these birds were from, but it was too soon for any released birds to be of breeding age (which is 4-6 years). One pair bred at the colony that year. Penguin numbers increased in 2023, with up to 20 moulting at the site and four pairs breeding. The growth of the colony was slowed in 2024, after a honey badger got through the fence and killed 11 penguins, several of which at the time were preparing to nest. However, one pair bred successfully despite this. The fence has since been reinforced, and no further predation has occurred. Two pairs have bred in 2025, successfully raising two chicks each (BirdLife, 2024).

De Hoop colony headland. (© Christina Hagen)

African penguin alongside soiled penguin decoy at new penguin colony at De Hoop. (© Christina Hagen)

NoteBox 5: Purse-seine fishery no-take zones around six major African penguin colonies.

Competition for common anchovy and sardine prey between African Penguins and commercial purse-seine fishers has been recognized as a significant threat to the African Penguin. This threat was suspected as early as the 1970s but it was not until 2008 that formal recognition of this threat was translated into action by the Department of Environmental Affairs and Tourism through the implementation of experimental ‘island closures’ including alternating 3-year open and closed periods around four major penguin colonies in two regions (Dassen and Robben islands on the west coast and St Croix and Bird islands in Algoa Bay) up until 2021. The results of this experiment demonstrated a meaningful effect of these closures to African penguin breeding success, although the experiment was limited in its ability to assess longer-term impacts of fishing closures on other important African Penguin population parameters such as survival. Despite these limitations and after a lengthy period of negotiations between the Department of Forestry, Fisheries and the Environment, the purse-seine fishing industry representatives and penguin scientists, including an international review of the scientific findings, between 2021 and 2024, no-take zones were implemented for a minimum of 10 years (pending reviews in 2031 and 2035) around six penguin colonies in 2025 (Figure 4 – Figure 6); these included the addition of the south coast colonies of Stony Point and Dyer Island (Figure 5). This resulted in meaningful closure extents, i.e. closure designs that incorporated the majority of important penguin foraging habitat, around at least one colony in each of the three major regions (Figure 4 – Figure 6).

Figure 4. Purse-seine fishing closures around Robben and Dassen islands on the west coast. (© BirdLife South Africa)

Figure 5. Purse-seine fishing closures around Stony Point and Dyer Island on the south coast. (© BirdLife South Africa)

Figure 6. Purse-seine fishing closures around St Croix and Bird islands in Algoa Bay. (© BirdLife South Africa)

Recommended citation

McInnes, A., Hagen, C., Faure, P., Angel, A., Wolfaardt, A., Adams, R., Van Der Colff, D., Monyeki, M.S., & Hendricks, S.E. 2025. Marine birds: Marine realm. National Biodiversity Assessment 2025. South African National Biodiversity Institute. http://nba.sanbi.org.za/.

References

1. Lee, A.T.K. et al. 2025. The 2025 red data book of birds of south africa, lesotho and eswatini, I., M. et al. (eds),. BirdLife South Africa, Johannesburg, South Africa.

2. Butchart, S.H.M. et al. 2004. Measuring global trends in the status of biodiversity: Red list indices for birds. PLoS Biology 2: https://doi.org/10.1371/journal.pbio.0020383